1. Field of the Invention
This invention relates to the use of electromyography (EMG) signals in electronic handwriting transcription.
2. Background
The prior art is rich in various systems and methods in the area of digital handwriting, as well as various systems and methods relating to useful endeavors. In general, most existing systems and methods provide concrete functions, which have a defined response to a defined stimulus. Such systems, while embodying the “wisdom” of the designer, have a particular shortcoming in that their capabilities are limited. The following is a description of some of these technologies.
Digital ink refers to technology that digitally represents handwriting in its natural form. In a typical digital ink system, a digitizer is laid under or over an LCD screen to create an electromagnetic field that can capture the movement of a special-purpose pen, or stylus, and record the movement on the LCD screen. The effect is like writing on paper with liquid ink. The recorded handwriting can then be saved as handwriting or converted to typewritten text using handwriting recognition technology.
Digital ink technology enables a user to write and draw on the touch-sensitive screen of a handheld PC or other writing tablet with a stylus or other pointing device, and for that information to be input into the computer, perhaps with some enhancements such as handwriting recognition or display. The technology provides a convenient means for applications to accept input from a user without using a keyboard. For a user, taking notes or drawing sketches using digital ink technology is a convenient way to enter text or other information into a computer without having to use a keyboard.
Most contemporary handwriting analyzers utilize a tablet computer and a stylus. A user writes on the tablet computer with the stylus, and coordinate, pressure, vector, and/or other information generated by the contact of the stylus with the tablet computer is utilized to recognize the writing strokes of the user. A problem with this system is that writing on a computer tablet does not feel the same as writing on paper. In addition, people prefer to write with more contemporary, ergonomic pens rather than with the thin stylus that is typically provided with a tablet computer.
A related technology provides an electronic module that inserts into or is otherwise associated with a pen or other writing instrument. The electronic module includes a mechanism for detecting pen motion, such as an accelerometer, and is preferably mounted in a cavity that is designed for a substitute ink cartridge for a pen. An accelerometer may be used to measure the relative acceleration and deceleration of the pen in the X and Y axes, which in turn may be used to provide a two-dimensional vector stream representing the pen's movement. Alternatively, the accelerometer may be arranged so that it senses tilt of the pen. In such a case, the information from the accelerometer may be used to plot relative X and Y components that represent the pen movements that are generated by a user.
Another example of similar technology is digital pen and paper technology, in which a digital pen writes on paper like any normal pen. The difference is that it captures everything the user writes. The pen can send what the user has written to a computer for storage and processing, or as an email or fax. Applications range from: removing the need to re-key forms, to automatically storing and indexing pages written in a note-book. The user can even send faxes and emails by simply writing them with a pen.
The digital pens include a tiny camera, some memory, a CPU and a communications unit. The paper is also special in that it needs to have an almost invisible dot pattern printed on it. The user could use a computer's printer to print this or get a specialist stationery printer to do it. Many paper products from 3M yellow Sticky Notes to Black n' Red Notebooks are already available with the pattern pre-printed on them. The pen senses the pattern and is thereby able to provide data as to where on the page the user is writing.
The disadvantage of tablet PC and PDA technologies is that it is not convenient for taking notes and drawing. The disadvantage of electronic pen and paper technology is that it requires special paper. The disadvantage of the accelerometer based technology is that it is not accurate and not reliable.
Using handwriting for taking notes and drawing is the most natural way of non-verbal communication. Hence, here is a demand for convenient ways to transfer handwriting into computers or cell phones.
Current methodologies, such as optical camera, ultra sound, and tablet technology, do not allow users to take full advantage of handwriting interfaces because they all require special pens. Optical cameras are not durable and need special paper. Ultra sound requires external device. An electronic tablet requires a computer, which takes away from the freedom of handwriting. A new approach is therefore needed for a convenient way to use digital handwriting products.
Digital pens based on optical camera technology use a tiny camera on the tip of the pen. It can write only on the specially designed paper. Users have to make a check mark in a special location, when they start, or stop writing. This type of pen uses special ink cartridge. Such optical cameras tend to break, when they are accidentally dropped. Users are not comfortable writing with special pens and on special paper.
Digital pens based on ultra sound technology transmit ultrasound to an external device that calculates the location of the pen. Again, the necessity to write only with a special pen and carry an external device makes this device inconvenient. Additionally, ultra sound technology is energy consuming, which imposes a limit on the paper size.
Electronic tablet technology requires using a special pen that writes on Tablet PC, or a special device that is connected to a computer. This technology is also not as convenient as traditional pen and paper.